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Modeling of Anaerobic Digestion with a Focus on Estimation of Hydrolysis Constants at 35, 55, and 60 °C
Author(s) -
Haghighatafshar Salar,
Ossiansson Elin,
Koch Konrad,
Kjerstadius Hamse,
Jansen Jes la Cour,
Davidsson Åsa
Publication year - 2015
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143014x14062131177999
Subject(s) - anaerobic digestion , chemistry , propionate , hydrolysis , anaerobic exercise , ammonia , chemical oxygen demand , kinetics , biomass (ecology) , methanogenesis , chromatography , pulp and paper industry , biochemistry , organic chemistry , methane , environmental engineering , wastewater , environmental science , biology , ecology , physiology , physics , quantum mechanics , engineering
Hydrolysis constants of mixed sludge at 35, 55, and 60 °C were found to be 0.32, 0.44, and 0.50 1/d, respectively, in pilot‐scale, semicontinuously operated anaerobic digesters. The hydrolysis constants and estimated chemical oxygen demand fractions in the feed were introduced to a mathematical model for anaerobic digestion published by Siegrist et al. (2002), which is similar to Anaerobic Digestion Model No. 1. First‐order and Monod‐type kinetics were tested for estimation of hydrolysis constants. The applied kinetics were found to affect the outcome of the regression study. Moreover, the free ammonia inhibition model was excluded for both propionate oxidation and acetate conversion, thanks to the apparent acclimatized biomass. No substantial accumulation of volatile fatty acids was observed in the reactors at 35, 55, and 60 °C, corresponding to free ammonia nitrogen concentrations of about 20, 110, and 130 g N/m 3 , respectively.